Scrubby has just the remedy for yucky toilet stains. Scrubbing Bubbles® Drop-Ins toilet cleaning tablets. Just drop a tablet into your tank to help keep your toilet bowl stain-free up to four weeks. With every flush, your toilet enjoys glorious relief from stains caused by hard water, minerals, and limescale. That's continuous stain protection for a continuous clean. Quick and hassle-free. Application: Toilets; Applicable Material: Non-Porous Surfaces; Chemical Compound: Sodium Dodecylbenzene Sulfonate; Dirt Types: Hard Water Stains; Limescale; Minerals.